NASA: I'm confused.

[geronimotwo]

Actually I think that was JFK and Breznev at the time, wasn't it? The non-weaponizing/militarizing of space has been a pretty constant agreement between the major powers since the original inception of space flight.




Except in this case the "growth or enlargement" is of the total distance between the Earth and Moon as held in balance by a combination of their masses, tangential velocities and the total Force of their gravitational attraction as adequately expressed in this case by Newton's law of universal gravitation (we only need to step up to Einstein's relativity for extraordinarily large masses):



The masses of the two objects multiplied, divided by their distance squared and multiplied by the gravitational constant gives the attractive force between them. With a sufficiently large addition of mass to one or both of the two masses in question you get an overall increase in that attractive force. This increase of force coupled with a reduction of that tangential velocity (which is what is overcoming the attractive force and keeping the two bodies in cicumnavigational orbit) due to the impacts of the masses being added to the primary masses in question would lead to the conclusion of a deceleration of the overall accretion of the Moon's distance from the Earth, however scant.

i know i'm out of the basic realm of my hs physics class, but, in addition to increasing the gravitational pull, wouldn't adding mass also add to the centripital (centrifical?) force being caused by the orbital velocity of the moon?  wouldn't these forces nearly equal if the mass(es) continued at the same velocity?

[kgbsquirrel]

i know i'm out of the basic realm of my hs physics class, but, in addition to increasing the gravitational pull, wouldn't adding mass also add to the centripital (centrifical?) force being caused by the orbital velocity of the moon?  wouldn't these forces nearly equal if the mass(es) continued at the same velocity?

Not necessarily. If the mass being added to the orbiting mass (lets call this the primary) was first brought to and matched the primary's speed and trajectory then you wouldn't really have a problem, you wouldn't be significantly affecting the primary's orbit, however in this case we are talking about objects with their own significant mass, energy and trajectory far different from the primary impacting  it forcefully. In this case the inertial energy of the primary (moon) can be increased if the impacting mass (rock) imparts a prograde force, ie. it impacts on the trailing face, also however the trajectory of the primary will be changed, even if  ever so slightly, because it will almost never strike exactly along the primary's original trajectory. If the impacting mass imparts a retrograde force (impacting on the leading face) though it would negate part of the inertial energy. Bear in mind the reason why we don't see any major change here is because the impacting mass and it's associated energy is absurdly minute compared to the moon. However if we scale this down to something the size of a satellite it becomes far more obvious and in fact imperative to account for.

The easiest example of an impacting mass imparting a retrograde effect on an orbiting object and causing it's orbit to decay (ie. slow down and then correspondingly lose altitude) would be a common communications satellite in low earth orbit. At those altitudes you still have to account and compensate for atmospheric drag (and magnetic drag, but lets keep things simple). As the several ton satellite proceeds through it's orbit at around 16-18,000 MPH it is constantly running into molecules of nitrogen, oxygen, argon, etc. not to mention the occasional bit of cosmic dust or errant meteorite. Despite the insignificance of their mass relative to the satellite's the effect is a constant retrograde (atmosphere) or instant variable (meteorite ) change in the satellite's velocity (in this case, the proper definition of velocity, speed and trajectory). Left unchecked the longest a sat has lasted in LEO is only 12 years. Now just scale the energies, masses, distances and time line up to something the size of the moon.

A shorter answer: If the impacting object gives the primary enough energy during the collision to account for it's own mass there is no problem. The trouble arises when the impacting object reduces the primary's energy (speed) while still adding to it's mass.


Edit to add:

Here's just something you may find interesting. The moon's orbit is not perfectly circular, it's actually slightly elliptical and the moon itself has a bit of wobble, likely due to a few billion year's worth of solar system creation and subsequent impacts (hey, that crap adds up after a while). Here is a .gif showing time lapse images of the moon as it passes through perigee and apogee (the closest and farthest points of it's orbit, respectively).....

[roo_ster]

Wasn't sure, so I went and looked it up again. It was SALT-II (Strategic Arms Limitation Treaty No. 2) in 1979 that banned the placement of nuclear weapons in orbit or fractional orbits.

The Senate never ratified SALT-II.  It is a worthless scrap of paper signed by a worthless POTUS.

[kgbsquirrel]

The Senate never ratified SALT-II.  It is a worthless scrap of paper signed by a worthless POTUS.

And yet neither of us have put nuclear weapons in orbit. Maybe common sense does exist?

ETA: The outer space treaty. Signed and ratified, '67/'68.

[Nick1911]

And yet neither of us have put nuclear weapons in orbit. Maybe common sense does exist?

Umm...  how do we know this for fact?

[roo_ster]

Umm...  how do we know this for fact?

We don't and just take their word for it...while we scrap the ASAT program.

Also, it is hardly common sense to cede the high ground.

[kgbsquirrel]

We don't and just take their word for it...while we scrap the ASAT program.

Also, it is hardly common sense to cede the high ground.

Orbital nukes are hardly high ground. With a high resolution radar it is easy enough to find anything you want in orbit, more so to detect something on a sub-orbital trajectory (hmm, I seem to recall a bunch of radars built over half a century ago that could do that). Try that against an SSBN hiding somewhere in the Pacific/Atlantic/Indian/Arctic, it's a bit harder to do. Practicality and survivability ranks nuclear weapon satellites somewhere below air breathing bombers, hardened silos, land/air mobile platform and submarine based systems.

[roo_ster]

Orbital nukes are hardly high ground. With a high resolution radar it is easy enough to find anything you want in orbit, more so to detect something on a sub-orbital trajectory (hmm, I seem to recall a bunch of radars built over half a century ago that could do that). Try that against an SSBN hiding somewhere in the Pacific/Atlantic/Indian/Arctic, it's a bit harder to do. Practicality and survivability ranks nuclear weapon satellites somewhere below air breathing bombers, hardened silos, land/air mobile platform and submarine based systems.

"High ground" encompasses more than just nukes.  To quote myself:

I am in favor of "going back to the moon" or elsewhere insofar as that is a military-themed and purposed effort.  Will it give America a leg up militarily?  Can we monopolize space-based military power?  Will it allow us to treat the treat of the solar system as our new frontier?  Can we implement a "Monroe Doctrine for the Solar System?"

Nukes on sats is likely the least significant use of military power in space, mid to long term.


But, in hte interests of debate....

Oh, I agree that finding planes & subs would be much more challenging.  But, "seeing" a satellite on radar and IDing it as a nuke-toting threat are two different critters.  Even if we got visual ID on some satellite we thought toted nukes, we very likely wouldn't blast it out of the sky, especially when the Chicoms/Russkies/Norks/etc. are claiming it is a "100% peaceful scientific research satellite designed to save fluffy puppies and children."

Nuke weapon satellites don't have to survive any more than the booster section of an ICBM has to after it has released its warheads.  Just drop their ordnance. After that, they are expendable.

Also, there is the small problem that we have very, very few missiles capable of reaching & killing satellites.  The ASAT missiles we tested back in the 1980s nailed satellites upwards of 550KM and the Chinese nailed one at that altitude in 2007.  The SM-III can't get that high.  Back in 2008 it had to wait until the dying satellite was low enough (~150KM) for it to take a stab at it.  About the only ones on hand are the GBIs that are part of the National Missile Defense, and those are located to intercept ICBMs mid-phase.  They might not be too useful in downing satellites over CONUS before the sats can release their warheads.  Some sats are in orbits higher than any country has successfully nailed a satellite.

It looks like we can (conservatively) wring out upwards of 1 megaton for every thousand pounds of warhead, given old-tech W53 (9 megaton/8000lbs) warheads.  I bet the USSR and China have achieved that level of efficiency in the 50 years since we developed the W53.  Given that the Canadians have launched a 6 ton / 12,000lb satellite, that is a whole lot of nuclear destruction.

Anyways, it is interesting to think on the topic.  If you have more data, do please share it.

[mellestad]

It doesn't even have to be nuclear.  Sure, putting a warhead on it makes a big boom, but a big metal rod with some fins on it dropped from orbit is going to ruin someone's day all on its own.

Personally, I'd like to see space non-weaponized.  Right now there isn't any reason to do it (it isn't at all cost effective, probably never will be compared to other methods), and do we *really* need to take war to space just because we can?

Honestly, I think a large part of why space has not been weaponized (and why the powers all have treaties banning the practice) is that it isn't that practical for the money.  I could be wrong though, that is just a guess.

Anti-satellite tech is probably a high priority right now though, as it should be.  Step one in a modern conflict between 1st world powers would probably be shooting down everything in orbit.

[roo_ster]

mell:

It is going to happen some time anyway.  Might as well get a jump on the competition. 

I recall reading about the early days of WWI, when all the pilots flew over the battlefield and waved at each other going by. 

Who'd want to weaponize the very air we breathe?  Well, everybody, once they were able to do so.  It went from bricks, to pistols, to rifles, to machine guns.

Who'd want to weaponize the internet?  Under the sea? 

Face it, anyplace folks can compete, they will eventually do so...and eventually do so to the death.

[kgbsquirrel]

Also, there is the small problem that we have very, very few missiles capable of reaching & killing satellites.  

Any of our current SLBM's (Trident D5's) or ICBM's (Minuteman-III's or Peacekeepers that haven't been fully converted to satellite lifters yet) are capable of lofting to that altitude. If you really, really, really needed a satellite killed, such as to keep New York/Moscow/Beijing/London from being nuked by a rogue third party, you could use one of those and their associated payload to kill the satellite. Like swatting flies with a bazooka, but it would definitely get the job done. Just be sure you ring up the rest of the nuclear powers on the red phone to let them know what you're doing first, mmkay? Besides, the Russians already came up with a way to kill satellites in orbit. Basically it's the satellite version of a claymore. They find your spy/mil comm satellite, drive this thing up next to it, and blam, swiss cheese it with a few thousand BB's.

A couple reasons why sats are worthless for long term strategic launch platforms are, the fact that major nation states can and do invest in finding out what sort of satellite assets other countries are operating and where they are, and that it becomes far more difficult to do periodic maintenance on the warheads. A nuke once built has a definite shelf life due to things such as radio active decay of key parts of the physics package. Add to their current maintenance requirements new ones due their constant exposure to thermal oscillations and their associated expansion/contraction stresses (remember, space is +200 degrees in sunlight and -200 degrees in the shade, and LEO orbits go through that cycle every couple hours).

Anyways, it is interesting to think on the topic.  If you have more data, do please share it.

I'm trying to stay open source on this.




On another note though, down the road once we've managed to make the hop from moon to mars to asteroid belt, high efficiency, low radiation nukes may actually be rather helpful for smashing apart the chunkier rocks that we want to mine. Perhaps replace the fission initiator with gram sized amounts of anti-matter and the rest as straight deuterium/tritium gas inside a container of a material that doesn't transmute to a radioactive isotope.

I think once we get to the point where we can actively mine the asteroid belt for some of the really nice elements we don't have very much of here on Earth, we'll start to see the private sector take over space flight big time. Follow the money, as they say. Right now the money is in communication satellites and the like, but not very much in going too much further than GEO. Once there's that monetary incentive though....

[mellestad]

mell:

It is going to happen some time anyway.  Might as well get a jump on the competition. 

I recall reading about the early days of WWI, when all the pilots flew over the battlefield and waved at each other going by. 

Who'd want to weaponize the very air we breathe?  Well, everybody, once they were able to do so.  It went from bricks, to pistols, to rifles, to machine guns.

Who'd want to weaponize the internet?  Under the sea? 

Face it, anyplace folks can compete, they will eventually do so...and eventually do so to the death.

hmm, maybe.  I know you are probably right, but right now no-one has anything to gain by weaponizing space.  Nothing to gain and a huge expense to do so.


I like to pretend humans are capeable of thinking for the greater good though, so take it for what it is worth.

[mellestad]

...

Is an ICBM really capable of hitting a satellite, I mean based on their accuracy?  Many of the satellites can maneuver too, and I imagine any carrying weapons certainly could.

I'm skeptical that our old ICBM's have that kind of tracking ability.

[kgbsquirrel]

Is an ICBM really capable of hitting a satellite, I mean based on their accuracy?  Many of the satellites can maneuver too, and I imagine any carrying weapons certainly could.

I'm skeptical that our old ICBM's have that kind of tracking ability.

If you know where the satellite is in it's orbit and what it's direction/speed/altitude is you can figure out where it's going to be a while down the road. Then you just take your ICBM, program it to launch at X time and fly on Y path that intersects the satellites path at Z. Considering those old missiles can get within 400 feet of it's intended target and has a blast range of several miles I'd say the chances of waxing said satellite are pretty good. Mind you that you're probably going to fry all nearby civi satellites with the EMP as well (with the lack of a significant atmosphere nuclear blasts tend to remain almost entirely as an EMP wave. During the high atmospheric tests over the south atlantic back in the 50's we accidentally knocked out communications in that area for a week through ionospheric disruption. Fun times!) Flight time will only be about half of what it would have taken since it's only completing half it's suborbital flight so.... 15-25 minutes from launch to detonation?

For the owner of said satellite to know that something big and nasty is coming it's way would require them to have assets for detecting strategic weapon launches. Generally only the prime nuclear powers have such things, so if you have a dinky little rogue state (DPRK?) putting a nuke launching sat in orbit they probably wont have a chance to shift it's orbit before it gets hosed.

[mellestad]

If you know where the satellite is in it's orbit and what it's direction/speed/altitude is you can figure out where it's going to be a while down the road. Then you just take your ICBM, program it to launch at X time and fly on Y path that intersects the satellites path at Z. Considering those old missiles can get within 400 feet of it's intended target and has a blast range of several miles I'd say the chances of waxing said satellite are pretty good. Mind you that you're probably going to fry all nearby civi satellites with the EMP as well (with the lack of a significant atmosphere nuclear blasts tend to remain almost entirely as an EMP wave. During the high atmospheric tests over the south atlantic back in the 50's we accidentally knocked out communications in that area for a week through ionospheric disruption. Fun times!) Flight time will only be about half of what it would have taken since it's only completing half it's suborbital flight so.... 15-25 minutes from launch to detonation?

For the owner of said satellite to know that something big and nasty is coming it's way would require them to have assets for detecting strategic weapon launches. Generally only the prime nuclear powers have such things, so if you have a dinky little rogue state (DPRK?) putting a nuke launching sat in orbit they probably wont have a chance to shift it's orbit before it gets hosed.

Hmm, I didn't know they were accurate to 400 feet.

But your blast range certainly isn't going to be several miles anyway is it?  Not in a vacuum?  And I would presume anything you were shooting at would probably be hardened, right?

[kgbsquirrel]

But your blast range certainly isn't going to be several miles anyway is it?

We are both talking about multi-megaton nukes here, right? 

[roo_ster]

We are both talking about multi-megaton nukes here, right? 

W53 Warhead
Yield: 9 megatons
Blast Radius: REALLY FREAKIN' LARGE! (waaaaay bigger than 400')

Yeah, I imagine that one of these puppies could take out a satellite or 20.


kgb:

I get your points, the most pertinent to me being the required maint over time and the huge temp variations.

Still doesn't mean we oughtn't claim the Moon as Space Port One. 

[kgbsquirrel]

Still doesn't mean we oughtn't claim the Moon as Space Port One. 

True. However if I am remembering right, some guy back in the 1970's already claimed the moon and registered it, deed and all. Ask PTK, I think he bought a single square foot of lunar real estate just because he could. 

[mellestad]

W53 Warhead
Yield: 9 megatons
Blast Radius: REALLY FREAKIN' LARGE! (waaaaay bigger than 400')

Yeah, I imagine that one of these puppies could take out a satellite or 20.

Certainly not more than one hardened platform.  Sure, it might get the one you are aiming at, but it isn't going to knock out a hardened orbiter at any great distance.  Most damage from a nuke comes from the shockwave and there isn't any shockwave in space.  You're mostly relying on the radiation at anything past a short distance.

http://www.projectrho.com/rocket/rocket3x1.html#nuke

http://www.5596.org/cgi-bin/nuke.php  <-- a 9 megaton weapon isn't going to do much against anything past 3,000 meters as long as it is hardened against EMP.

So again, if a ground silo nuke could really put an ICBM close to an orbital weapons platform, it would probably do the job.  The problem I see is that any major power is probably going to have platforms that can evade to some degree (I'm not sure if it is worth a good idea to plan on rogue or third world states putting simple and dumb weapons platforms in orbit), and I don't think your typical ICBM can even track a moving target can it (I don't know why they would have made it able to do that when they were built)?  And at the ranges we're talking about and the speeds a platform is moving it wouldn't be hard to evade, especially since ICBMs are not designed as interceptors.


I'm not saying they couldn't do the job, but they wouldn't be ideal.  You'd probably want 'small', light interceptors that were cheap enough to launch a couple per target.

[S. Williamson]

There are other techniques that could be used in "weaponizing" space.  Nuke platforms, as already discussed, offer no real advantage over cheaper and easier-to-deploy surface-based methods.

However, one thing that space is used extensively for so far is real-time intel, i. e. spy satellites. 

A simple vessel, with standard RCS/LIN maneuvering capability, remotely operated, with an M197 cannon retrofitted for vacuum (complete with automated recoil-canceling software for the RCS thrusters), and/or AGM-88 HARMs retrofitted for vacuum and/or AN/ALQ-99s for anti-spy/ anti-communications satellite operations could seriously kick some arse.

[MechAg94]

The other thing about ICBMs I was thinking of:  Aren't they simply designed to boost into a short orbit and release warheads that essentially guide themselves into reentry onto specific targets?  I would think a redesign of the warhead would be required at the very least to release it in orbit and send it after a satellite.  I also wouldn't think a typical ICBM was even designed for one orbit.  Just get high enough and far enough to drop warheads into re-entry.  Is it going to reach geosynchronous orbit altitudes?

[kgbsquirrel]

The other thing about ICBMs I was thinking of:  Aren't they simply designed to boost into a short orbit and release warheads that essentially guide themselves into reentry onto specific targets?  I would think a redesign of the warhead would be required at the very least to release it in orbit and send it after a satellite.  I also wouldn't think a typical ICBM was even designed for one orbit.  Just get high enough and far enough to drop warheads into re-entry.  Is it going to reach geosynchronous orbit altitudes?

Yes they are capable of reaching LEO and MEO altitudes. Your payload would need an additional on board booster to reach either one of the two GEO's. For HEO's you could just need to wait for the satellite to approach perigee. Former ICBM's are commonly converted into satellite lifters in swords to plowshares programs. Also you may enjoy reading up on the Soviet R-36, GR-1 (SS-X-10 Scrag) and R-46. Also for a fun math exercise find the following, if an orbit is traveling in a parabolic arc and returns to earth 6000 miles from it's starting point, what is it's highest attained altitude?

[kgbsquirrel]

The problem I see is that any major power is probably going to have platforms that can evade to some degree...

No major power has bothered with this sort of item since the '60s, an even then it was fractional orbit systems that were only launched when intended to be dropped on someone, not put into a holding orbit waiting for a Premier to push the red button. Also I think you are grossly overestimating the amount of EMP hardening satellites get. Adding shielding adds mass, and since you have a definite limit on payload you have to sacrifice something else, maneuvering fuel or operational payloads for instance. Most satellites have just enough radiation shielding to keep them from frying when passing through the Van Allen radiation belt in the south atlantic anomaly or a solar prominence. However, and despite the inverse square law which I'm quite aware of, detonating a multi-megaton nuke within a couple miles of a target would still create enough of an induced current in the target satellites electronics as to cause it all sorts of problems, not to mention the extremely sensitive electronics of any on board warheads.

I might also point out that before the recent attempts at non-nuclear, small scale, low cost ABM's the staple ABM systems of both the Soviets and the U.S. were nuclear armed. For example the Nike Zeus, renamed Spartan, was mounted with a 5mt warhead and killed the incoming warheads using an x-ray burst outside the atmosphere (where most of a nuclear weapons yield remains as x-rays). They was also an intra-atmosphere missile called Sprint that used a much smaller but enhanced radiation warhead.

[mellestad]

No major power has bothered with this sort of item since the '60s, an even then it was fractional orbit systems that were only launched when intended to be dropped on someone, not put into a holding orbit waiting for a Premier to push the red button. Also I think you are grossly overestimating the amount of EMP hardening satellites get. Adding shielding adds mass, and since you have a definite limit on payload you have to sacrifice something else, maneuvering fuel or operational payloads for instance. Most satellites have just enough radiation shielding to keep them from frying when passing through the Van Allen radiation belt in the south atlantic anomaly or a solar prominence. However, and despite the inverse square law which I'm quite aware of, detonating a multi-megaton nuke within a couple miles of a target would still create enough of an induced current in the target satellites electronics as to cause it all sorts of problems, not to mention the extremely sensitive electronics of any on board warheads.

I might also point out that before the recent attempts at non-nuclear, small scale, low cost ABM's the staple ABM systems of both the Soviets and the U.S. were nuclear armed. For example the Nike Zeus, renamed Spartan, was mounted with a 5mt warhead and killed the incoming warheads using an x-ray burst outside the atmosphere (where most of a nuclear weapons yield remains as x-rays). They was also an intra-atmosphere missile called Sprint that used a much smaller but enhanced radiation warhead.

If we are speculating on weapons platforms that do not yet exist, isn't it appropriate to speculate on what they would likely consist of?  Even without heavy shielding I can't imagine a weapons platform wouldn't be able to shift ten kilometers off course in the time it would take an ICBM to intercept.  At the speeds they would be orbiting at, I imagine they could shift position radically, and it isn't like they need to be concerned about saving reaction mass if someone is already trying to shoot them down with an ICBM, all they need to do is shift far enough to dump their payload. 

I agree, if you want to make a new class of nuclear interceptor it would work fine, but we were talking about using existing ICBMs.  I imagine there are a lot of questions anyway.  How fast could a ground based ICBM complex target a satellite?  Fast enough to matter in an actual situation?  How fast could it go from a non-alert status to putting a missile in orbital altitude?  Fast enough to matter?

I imagine someone somewhere has actually figured out whether this is possible though, if anyone sees anything please link it, since I am talking out of my rectum.

[MechAg94]

Yes they are capable of reaching LEO and MEO altitudes. Your payload would need an additional on board booster to reach either one of the two GEO's. For HEO's you could just need to wait for the satellite to approach perigee. Former ICBM's are commonly converted into satellite lifters in swords to plowshares programs. Also you may enjoy reading up on the Soviet R-36, GR-1 (SS-X-10 Scrag) and R-46. Also for a fun math exercise find the following, if an orbit is traveling in a parabolic arc and returns to earth 6000 miles from it's starting point, what is it's highest attained altitude?

Okay, I thought that altitude was pretty low by comparison to more stable orbits.  Either way, the ICBM idea is still using a heavily modified ICBM or warhead, not just one out of the silo.